KR20170000938U

KR20170000938U - Magnetic Switch

Info

Publication number: KR20170000938U
Application number: KR2020150005899U
Authority: KR
Inventors: 이경준
Original assignee: 엘에스산전 주식회사
Priority date: 2015-09-03
Filing date: 2015-09-03
Publication date: 2017-03-13

Abstract

The present invention relates to an electromagnetic switch, and more particularly, to an electromagnetic switch having an improved operating voltage by increasing a contact area between a fixed core and a movable core.
According to an embodiment of the present invention, an electromagnetic switch includes: a coil connected to a power source; A fixed core magnetized by a magnetic field generated around the coil when the power source is applied; A movable core capable of being attracted by a magnetic force generated in the fixed core; A movable shaft coupled to the movable core and moving together with the movable core, and connected to the movable contact at an upper end; A cylinder installed to surround the fixed core and the movable core; And a return spring installed between the lower end of the movable core and the bottom surface of the cylinder and returning the movable core to the original position when the power is interrupted.

Description

{Magnetic Switch}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic switch, and more particularly, to an electromagnetic switch having an improved operating performance by increasing a contact area between a fixed core and a movable core.

Generally, a magnetic switch (also referred to as an electromagnetic contactor or a direct current relay) is a kind of an electric circuit switching device which transmits a mechanical signal and a current signal using the principle of an electromagnet , Various industrial facilities, machines and vehicles.

Particularly, electric vehicle relays are located in the battery system of electric vehicles such as hybrid vehicles (HYBRID), fuel cell cars, golf carts and electric forklifts, and serve to open and close the main current.

FIG. 1 is a longitudinal sectional view of an electromagnetic switch according to the prior art, and FIG. 2 is a top view of the movable core in FIG.

An electromagnetic contactor for an electric vehicle includes an arc chamber 1, a pair of stationary contacts 3 provided in the arc chamber 1, a pair of stationary contacts 3 installed linearly in the arc chamber 1, And an electric actuator for driving the movable contact 4 so as to be able to control the opening and closing of the contact by means of an electric signal, which includes a movable contact 4 which contacts or separates from the contact 3. The actuator includes a coil 5 and a fixed core 6 and a movable core 7 which is attracted to a fixed core 5 which is magnetized by a magnetic field generated when a current flows through the coil 5 . A movable shaft 8 is coupled to the movable core 7 to be able to move vertically through the fixed core 6 and the movable contact 4 is coupled to the upper end of the movable core 7 to thereby move the movable contact 5 Exercise.

That is, when a power is supplied to the coil 5, a magnetic field is generated around the coil 5, whereby magnetic force is amplified in the fixed core 6 and the movable core 7 is attracted to the fixed core 6 And the movable contact 4 is brought into contact with the stationary contact 3 to allow a current to flow to the load side. On the other hand, when power is not supplied to the coil 5, the return spring 9 is provided between the fixed core 6 and the movable core 7 so that the movable core 7 returns to the downward position. The return spring 9 is inserted into the groove 6a formed in the lower portion of the fixed core 6 and the groove 7a formed in the upper portion of the movable core 7.

As described above, there is a return spring 9 in the electromagnetic switch for assisting return of the movable core 7 when the electromagnetic switch is turned off. The return spring 9 prevents an erroneous operation (unwanted on operation) caused by an external shock in the off state, and determines the shutoff performance by determining the off operation time. However, since the mounting position of the return spring 9 is located between the fixed core 6 and the movable core 7 that generates the driving force of the actuator, the contact area between the fixed core 6 and the movable core 7 is reduced Which causes the operating voltage to rise. Referring to FIG. 2, on the upper surface of the movable core 7, a loss of an area 'A' is generated by the groove 7a. 'A' approximately 10 to 15% of the upper surface of the movable core 7.

That is, in the electromagnetic switch according to the related art, as the return spring 9 is positioned between the fixed core 6 and the movable core 7, the contact area between the fixed core 6 and the movable core 7 Loss is generated, which causes a rise in the operating voltage. In other words, under the same voltage, there is a problem that the action force is decreased and the operation performance is lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an electromagnetic switch that improves the operation performance by providing a return spring under the movable core to increase the contact area between the fixed core and the movable core.

According to an embodiment of the present invention, an electromagnetic switch includes: a coil connected to a power source; A fixed core magnetized by a magnetic field generated around the coil when the power source is applied; A movable core capable of being attracted by a magnetic force generated in the fixed core; A movable shaft coupled to the movable core and moving together with the movable core, and connected to the movable contact at an upper end; A cylinder installed to surround the fixed core and the movable core; And a return spring installed between the lower end of the movable core and the bottom surface of the cylinder and returning the movable core to the original position when the power is interrupted.

Here, the return spring is a tension coil spring.

In addition, a seating part capable of providing a lower end of the return spring is formed on a bottom surface of the cylinder.

A first protrusion is formed on an inner circumferential surface of the seating part to fix a lower end of the return spring.

In addition, a fixing means is provided on a lower surface of the movable core to fix the upper end of the return spring.

Further, the fixing means is constituted by a stationary ring.

Further, a through hole is formed in the bottom surface of the cylinder.

In addition, a cap inserted into the through hole is provided.

A second protrusion is formed on the inner circumferential surface of the cap to fix the lower end of the return spring.

According to an embodiment of the present invention, since the return spring is provided at the lower portion of the movable core, the insertion groove formed in the conventional movable core and the fixed core is removed, thereby increasing the contact area between the movable core and the fixed core. . Thus, the operation performance is improved.

In addition, the engagement surface between the movable core and the movable shaft is increased to improve the coupling force, and the linearity is improved during the ascending / descending motion.

1 is a longitudinal sectional view of an electromagnetic switch according to the prior art.
Fig. 2 is a top view of the movable core in Fig. 1. Fig.
3 is a longitudinal sectional view of an electromagnetic switch according to an embodiment of the present invention. off state.
FIG. 4 is a longitudinal sectional view of an electromagnetic switch according to an embodiment of the present invention during on operation. FIG.
5 is a detailed view of the lower portion of the cylinder in Fig.
6 is a detailed view of a lower portion of a cylinder of an electromagnetic switch according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, which are intended to illustrate the present invention in such a manner that a person skilled in the art can easily carry out the present invention. And does not mean that the technical idea and category of the design is limited.

3 and 4 are longitudinal cross-sectional views of an electromagnetic switch according to an embodiment of the present invention. FIG. 3 shows an off state, and FIG. 4 shows an on state. 5 is a detailed view of the lower portion of the cylinder in Fig. The electromagnetic switch according to one embodiment of the present invention will be described in detail with reference to the drawings.

The electromagnetic switch according to an embodiment of the present invention includes a coil 35; A fixed core (40) magnetized by a magnetic field generated around the coil (35) when power is applied; A movable core (45) which can be attracted by a magnetic force generated in the fixed core (40); A movable shaft (20) coupled to the movable core (45) to move together and connected to the movable contact (12) at an upper end; A cylinder 65 installed to surround the fixed core 40 and the movable core 45; And a return spring 50 installed between the lower end of the movable core 45 and the bottom surface of the cylinder 65 and returning the movable core 45 to its original position when power is interrupted.

An arc chamber (10) is provided in the upper part of the electromagnetic switch for extinguishing an arc generated when the contact part is cut off. The arc chamber 10 may be formed in a box shape having an open bottom, and may be formed of a material having excellent insulation, heat resistance, and pressure resistance.

The stationary contact 11 is fitted in the upper part of the arc chamber 10 and is a terminal connected to a load or a power source for controlling power supply. These fixed contacts 11 are installed side by side in pairs.

The movable contact 12 is inserted into the arc chamber 10 and is contacted with or separated from the stationary contact 11. The movable contact 12 contacts the lower terminal of the fixed contact 11 described above. The movable contact 12 is a plate-like body having a predetermined thickness and a flat surface contacting the stationary contact 11. The movable contact 12 is fixed to the movable shaft 20 and contacts or separates from the fixed contact 11 as the movable shaft 20 linearly drives in the axial direction to energize or cut off the electric current. A hole is formed in the center of the movable contact 12, and one end of the movable shaft 20 is connected through the hole.

The arc chamber plate (13) is coupled to the lower portion of the arc chamber (10).

A plate 16 is provided under the arc chamber plate 13 with an elastic support 25 interposed therebetween. The plate 16 is formed as a flat plate, and a hollow portion is formed at the center thereof to support and support the arc chamber 10, the arc chamber plate 13, and the elastic supporter 25. In addition, the plate 16 fixes and holds the stationary core 40.

A sealing member (14) is coupled between the arc chamber (10) and the plate (16). The sealing member 14 is formed to surround the lower end surface of the arc chamber 10 and functions to seal a space formed by the arc chamber 10 and the plate 16. The sealing member 14 is preferably joined by welding or the like in order to ensure the airtightness of the inner space.

A cylinder 65 is coupled to the lower portion of the plate 16. The movable shaft 20, the fixed core 40, the movable core 45 and the like are inserted into the cylinder 65 and serve to form an airtight space in the lower portion of the plate 16. The cylinder 65 is preferably welded to maintain airtightness with the lower portion of the plate 16. According to the laser welding method, the manufacturing will be simplified. The cylinder 65 also serves to guide the movable core 45 and the movable shaft 20 coupled to the movable core 45 when they move up.

As a result, the arc chamber 10, the sealing member 14, the plate 16 and the cylinder 65 in which the stationary contact 11 is fitted form a closed airtight space, and the airtight space is filled with insulating gas, .

The actuator is a driving device that generates a driving force by a magnetic force and drives the movable contact 12 to contact or separate the fixed contact 11. The actuator includes a stationary core 40 fixed to the plate 16, a movable core 45, a bobbin 30, a coil 35, a movable shaft 20, and a return spring 50.

A cylinder 65 is disposed at the center of the actuator, and a bobbin 30 is installed to surround the cylinder 65.

The bobbin 30 has a cylindrical shape with flanges formed at the upper and lower ends thereof, and the above-described coil 35 is wound between the flanges of the bobbin 30. The bobbin (30) is also provided with a through hole capable of receiving the cylinder (65) along the central axis.

The coil 35 is wound around the bobbin 30 and a magnetic field is generated around the coil 35 when power is applied.

The stationary core 40 is provided inside the coil 35, specifically inside the cylinder 65. The fixed core 40 is a cylindrical body, and a first through hole 41 is formed along the central axis so that the movable shaft 20 is linearly drivable. At this time, the size of the first through-hole 41 is formed to be slightly larger than the outer diameter of the movable shaft 20. Therefore, since the movable shaft 20 does not contact the stationary core 40 during up-and-down movement, friction does not occur. On the other hand, the fixed core 40 is magnetized by the magnetic field generated by the coil 35.

The movable core 45 is also referred to as an armature and is a cylindrical body having the same diameter as the fixed core 40 described above and a second through hole 46 is formed along the central axis, . At this time, the movable core (45) is fixedly coupled to the movable shaft (20). That is, the movable core 45 moves integrally with the movable shaft 20. When a current flows through the coil 35, a magnetic force is generated in the fixed core 40, so that the movable core 45 is attracted to the fixed core 40 together with the movable shaft 20, and current flows through the coil 35 The movable core 45 is lowered to the initial position.

The insertion groove for installing the return spring, which is provided in the conventional art, is removed from the fixed core 40 and the movable core 45. Therefore, the contact area between the fixed core 40 and the movable core 45 is increased. As a result, the magnetic force is increased and the operation performance is improved. In addition, the mating surfaces of the movable core 45 and the movable shaft 20 are increased to improve the coupling force. Accordingly, when the movable core 45 moves integrally with the movable shaft 20, the straightness is improved, and the movement of the movable core 45 is reduced and the linear motion is assured.

The movable shaft 20 is a rod-shaped long shaft, the movable contact 12 is fixed to the upper end thereof, and the movable core 45 is fixed to the lower end thereof. The movable shaft 20 passes through the fixed core 40 and moves along the axial direction. The movable shaft 20 is formed with a flange 21 at a position spaced apart from the upper end by a predetermined distance. A contact spring 15 is provided between the flange 21 and the movable contact 12 to provide contact pressure when the movable contact 12 contacts the fixed contact 11. The flange 21 is hooked on the upper end of the arc chamber plate 13 and serves as a latching jaw for preventing the movable shaft 20 from further moving downward.

The above-described actuator is not limited to this configuration, and may be any structure that allows the movable shaft 20 to be linearly driven in the axial direction by the magnetic force to bring the movable contact 12 into contact with or separate from the stationary contact 11.

Referring to Fig. 5, a return spring 50 provided at the lower portion of the cylinder 65 is shown in detail. A return spring (50) for restoring the movable core (45) is provided below the movable core (45). Here, the return spring 50 may be constituted by a tension coil spring. Accordingly, the elastic force can be stored while being held in the compressed state at normal time (off time) and extended by the movable core 45 at the time of on operation. 3, the return spring 50 is in a steady state at a position where the movable core 45 is spaced from the fixed core 40, and the movable core 45 is fixed to the fixed core 40 40 so as not to contact the movable core 45. 4, the resilient force is stored as the return spring 50 is extended by the upward motion of the movable core 45, and when the moving force of the movable core 45 is removed by the cutoff operation or the off operation, The movable core 45 is quickly returned to the original position downward by the restoring force of the spring 50.

A seating portion 66 on which the lower end of the return spring 50 can be installed may be formed on the bottom surface of the cylinder 65. Here, the seat portion may be composed of a ring, a rib, or the like.

A first protrusion 67 capable of fixing the lower end of the return spring 50 may be formed on the inner circumferential surface of the seating portion 66. The first protrusion 67 may be formed of a plurality of protrusions or annular protrusions.

The lower surface of the movable core 45 may be provided with fixing means to which the upper end of the return spring 50 can be fixed. Here, the fixing means may be composed of a stationary ring 68. The fixing ring 68 can be fitted in the insertion groove 47 formed in the lower portion of the movable core 45 in an interference fit manner. Also, although not separately shown, the fixing ring 68 may be screwed or welded to the movable core 45 or the movable shaft 20 to increase the coupling force.

In other words, the return spring 50 has the upper end fixed to the lower portion of the movable core 45, and the lower end fixed to the bottom surface of the cylinder 65. [ Accordingly, when the movable core 45 moves upward due to the magnetic force generated in the fixed core 40, the elastic force is stored. When the magnetic force generated in the fixed core 40 disappears, The core 45 is quickly returned to the home position.

Since the return spring 50 is provided at the lower portion of the movable core 45, the insertion groove formed at the contact portion between the conventional movable core 45 and the fixed core 40 is removed and the movable core 45 and the fixed core 40 The contact area is increased, so that the reduction of the operating voltage is prevented. Thus, the operation performance is improved.

In addition, the engagement surface between the movable core 45 and the movable shaft 20 is increased, so that the coupling force is improved. In addition, there is an effect that the straightness is improved during the upward and downward movement.

6 shows an electromagnetic switch according to another embodiment of the present invention.

In this embodiment, a through hole 69 is formed in the bottom surface of the cylinder 65. A plug 70 is provided in the through hole 69. The cap 70 may be constituted by a ring-shaped body portion 71 fitted in the through hole 69 and a disk-shaped head portion 72 exposed to the outside of the cylinder 65.

A second protrusion 73 can be formed on the inner circumferential surface of the cap 70 to fix the lower end of the return spring 50. Like the first protrusion 67, the second protrusion 73 may be formed as a plurality of protrusions or annular protrusions.

Since the stopper 70 is provided on the bottom surface of the cylinder 65, if necessary, the stopper 70 can be detached and the inside of the cylinder 65 can be repaired.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the technical idea of the present invention, and the scope of technical idea of the present invention is not limited by these embodiments. That is, the scope of protection of the present invention should be construed according to the following claims, and all technical ideas which are within the scope of the same should be interpreted as being included in the scope of the present invention.

10 arc chamber 11 fixed contact
12 movable contact 13 arc chamber plate
14 sealing member 15 contact spring
16 plate 20 movable shaft
21 Flange 25 Elastic support
30 bobbin 35 coil
40 Fixed core 41 First through hole
45 movable core 46 second through hole
47 Insertion Groove 50 Return Spring
65 cylinder 66 seat part
67 First protrusion 68 Retaining ring
69 Through-hole 70 plug
71 body portion 72 head portion
73 Second protrusion

Claims

A coil connected to the power source;
A fixed core magnetized by a magnetic field generated around the coil when the power source is applied;
A movable core capable of being attracted by a magnetic force generated in the fixed core;
A movable shaft coupled to the movable core to move together and having an upper end connected to the movable contact;
A cylinder installed to surround the fixed core and the movable core; And
And a return spring installed between a lower end of the movable core and a bottom surface of the cylinder to return the movable core to an original position when power is interrupted.

The electromagnetic switch according to claim 1, wherein the return spring is a tension coil spring.

The electromagnetic switch as set forth in claim 1, wherein a seating portion capable of mounting a lower end of the return spring is formed on a bottom surface of the cylinder.

4. The electromagnetic switch according to claim 3, wherein a first protrusion is formed on an inner circumferential surface of the seat portion to fix the lower end of the return spring.

The electromagnetic switch as set forth in claim 1, wherein a fixing means capable of fixing an upper end of the return spring is provided on a lower surface of the movable core.

5. The electromagnetic switch according to claim 4, wherein the fixing means comprises a stationary ring.

The electromagnetic switch according to claim 1, wherein a through hole is formed in the bottom surface of the cylinder.

The electromagnetic switch according to claim 7, further comprising a stopper inserted into the through hole.

9. The electromagnetic switch according to claim 8, wherein a second protrusion is formed on an inner circumferential surface of the stopper, the second protrusion being capable of fixing a lower end of the return spring.